An important consideration in Alcohol and other Drug (AOD) treatment outcomes for adolescent substance abusers is motivation for treatment. This concept includes both external motivators such as legal coercion and the degree of intrinsic motivation, or inner reasons to change. While these motivating factors are thought to be essential to the understanding of treatment outcomes for adolescents, it is still not well understood how exactly motivation operates to affect outcomes. The main objective of the proposed study is to examine how external factors (legal coercion and other extrinsic pressures such as family and peers) and intrinsic motivation influence 12-month treatment outcomes for adolescents receiving publicly funded AOD reatment services. Specific aims are: (1) Examine and compare the roles of legal coercion (and other extrinsic pressures) and intrinsic motivation for treatment on client outcomes of AOD use (including dependency and abuse), negative consequences of AOD use, social, behavioral, and emotional functioning, and school attendance; (2) Separate the indirect effects mediated by treatment retention and continuity of care from the direct effects on the 12-month outcomes; and (3) A secondary aim will be to determine the effects of managed care on treatment retention and continuity of care for a 12-month period. The data set or this secondary data analysis is from the Massachusetts adolescent study, Teen Wellness in Services and treatment (TWIST) which recruited and followed a sample of 293 adolescents entering both residential (83.3%) and outpatient (16.7%) AOD treatment facilities. The TWIST data set combines client administrative data from the state treatment system, the managed behavioral health program and Medicaid with outcome data collected from in-depth structured interviews with adolescents during treatment (baseline) and two six- month follow-up intervals (follow-up rates: 6 months, 90%; 12 months, 88%). The proposed study will enable us to examine 12-month service use and outcomes using a rich database of client interview and administrative data. Better understanding of how motivational factors influence treatment outcomes will be useful for selecting the treatment program that is best suited to a particular client.